High smoke point frying oil



United States Patent 25,488 HiGl-l SMOKE POINT FRYING GIL Vigen K.Bubnyun, Livingston, NJ, assignor to E. F. Drew 8; Co., Inc, New York,N.Y., a corporation of Delaware No Drawing. Uriginnl No. 2,993,319,dated Aug. 29, 1061, Ser. No. 652,034, Apr. 11, 1957. Application forreissue Apr. 5, 1962, tier. No. 1003M 11 Claims. (Cl. S9llli} Niatterenclosed in heavy brackets E 1 appears in the original patent but formsno part of this reissue specification; matter printed in italicsindicates the ucditons made by reissue.

The present invention relates to a new and improved product adapted foruse for deep fat frying of food. More particularly, the inventionrelates to vegetable oils which have improved smoking characteristicsand may be utilized in many industrial and household uses whereheretofore excessive smoking made their use undesirable.

In the vegetable oil industry, for years dilliculties have beenencountered due to the smoking tendencies of oils subjected to elevatedtemperatures. For instance, in frying operations where temperatures of375 F. to 425 F. and higher may be employed, certain oils such as corn,cottonseed and peanut oil are now extensively used for frying operationssince the extent of their smoking is considered fairly moderate.Hydrogenated oils, stearines, shortenings, are also used in fryingoperations since their smoking tendencies are somewhat superior to thatof the former group. In both groups their excessive smoking is still anundesirable factor which one would prefer to eliminate or reduceappreciably. Smoking causes manufacturing operations to be difficult andthe food being fried to char or have an objectionable taste. It is alsomessy and in general undesirable on a large scale frying operation,causing breakdown and decomposition of the oil on prolonged heating.

In contrast to the above groups, oils such as coconut, babassu, tucumand palm kernel, included in the coconut type of oil, have been found toshow substantial smoking when used in the high temperature fryingoperations. Although they otherwise exhibit excellent flavor, stabilityand storage qualities, these oils have not found extensive use as fryingoils because of their smoking tendencies.

The present invention is intended and adapted to overcome thedilliculties and disadvantages inherent in prior compositions of thetype described, it being among the objects thereof to provide a productwhich does not develop smoke or disagreeable odor during trying operations.

It is also among the objects of the present invention to provide acomposition in which the improved smoke point characteristics are oflong duration and in which the frying operation may be conducted at hightemperatures without undesirable elfects.

It is further among the objects of the present invention to provide acomposition of a coconut type oil which heretofore has not been suitablefor commercial frying and make it available for such use by greatlyreducing the smoking tendency thereof.

The invention comprises the following: The vegetable oils describedabove are treated with a small amount of an agent capable of beingintimately dispersed in the oil. The agent is preferably dispersed bythe use of a homogcnizer, a colloid mill or similar device capable ofadequately mixing and intimately dispersing the agent in the oil. Theagent may be dispersed in a small volume of the oil and then thisconcentrate can be used to blend the entire batch being modified.Concentrations from 1 to 2 parts per million to several thousand partsper million may be employed but generally concentrations of ReissueclNov. 26, 1963 "ice to 30 parts per million give satisfactory results,for example, 10 parts per million.

The class of compounds capable of bringing about this increase in thesmoke point in the vegetable oils at frying temperatures are thesilicone oils (organo polysiloxanes). reaction products of silanes.These silicone oils when used in viscosity ranges of {11. 00} 100ccntisioltcs to about 100,000 ccntistokcs at i170 1 and in the minutequantities mentioned above, have the property of reducing or inhibitingthe smoking tendencies of vegetable oils at the elevated temperatures.

Silicone oils having viscosities below 1,000 centistokes, although theyshow improved smoke point tendencies, do not produce a permanent effectand, therefore, they cannot be considered satisfactory for improving thesmoke point. Silicone oils having viscosities above 100,000 centistokespresent processing diihculties which make their use impractical. Thesilicone oils of high viscosity show progressively less tendency tobecome dispersed in the vegetable oil and present a proccssing.dispersing and problem. One may be able by diligent blending, mixing andprocessing to get these high viscosity oils eventually dispersed in thevegetable oil but on standing the silicone oil may come out of solutionor dispersion and form an insoluble globule on the surface of thevegetable oil or at the bottom of the container.

One may employ carrier or coupling agents to blend the high viscositysilicone oils or even use silicone greases and silicone polymersapproaching gels and elastorners but their use also leads to otherundesirable considerations. in the preferred viscosity ranges indicatedabove. one is able to adequately disperse the silicone oil into thevegetable oil in the concentrations contemplated merely by the use of acolloidal mill or a homogenizer. The resulting oil is a homogeneous,clear oil showing no detectable dilfcrcnce when compared to the originalvegetable oil. The small amount of silicone oil used, for example 10 toparts per million, can only be detected when one resorts to specific,sensitive, analytical testing methods.

The silicone oils which are especially adapted for the present inventionare the methyl and ethyl polysiloxancs. The range of viscosities ofthese polysiloxancs which are adapted for the present purpose is quitelimited. For in stance, the methyl polysiloxnnes in order to be suitableneed have viscositics ranging from {1,000} 100 to 100,000 centistokes at100 F, the preferable range being between 1.000 and 30,000 centistokes.The ethyl polysiloxunes should have the viscosities ranging from [1,000]100 to 100,000 centistokes at 100 F. with the preferable range beingbetween W000 and 50,000 centistokcs.

Only small amounts of such compounds are desirable to give the maximumeffectiveness of the composition. in the case of the methylpolysiloxanes, from 1 to parts per million of the oil being treatedgives excellent results. The most preferred range is from 5 to 20 partsper million. In the case of the ethyl polysiloxanes, from 5 to parts permillion is suitable and the preferable range is from 15 to 45 parts permillion. The additives contemplated herein imparting the improved smokepoint characteristics to the vegetable oils have the general formula asfollows:

wherein R is a radical taken from the class consisting of methyl andethyl and n is at least 10 and sufficiently large so that the saidcompounds has a viscosity of about {10001 to M10000 ccntistokcs at 100F., the amount of said compound being sufficient to substantially reducethe smoking tendencies of said oil at the elevated temperatures used infrying foods.

The following table shows comparative results on the smoke point risedue to the addition of various amounts of methyl polysiloxanes havingviscosities ranging from 100 to 100,000 CBIttiSlOkfiS. The examplesshown below were run on cottonseed oil.

lLiLlil,

\isc. in Methyl lolysilnxttne added ill-111k The above compositions wereprepared by mixing master batches of H10 parts per million of each ofthe various viscosities of silicone oils in cottonseed oil and blendingin an Eppenbach mill at maximum rpm. for live minutes. Dilutions ofthese solutions were then made to obtain the desired concentrationrange.

The smoke point was determined in each case in accordance with themethod promulgated by the American Oil Chemists Society as MethodCc9ai8.

After repeated fryings, it was found that the smoke point riseengendered by the 100 centistoke viscosity siloxane was not permanent.

It was also noted that the 100,000 centistoke viscosity oil was blendedWith great ditliculty and although it is effective to raise the smokepoint, as a practical matter it is too viscous for easy commercialhandling.

It should be noted that the foregoing example represents the preferredform of the invention, namely the use of methyl polysiloxane as opposedto ethyl polysiloxane.

Further test were conducted on various other types of vegetable oilsusing the optimum viscosity of 10,000 centrstokes and the optimumconcentration of 10 parts per million. The results of those experimentsare tabulated below:

It is quite apparent from the foregoing that these additives arecilcctive on all types of vegetable oils.

The phenomenon of excessive smoking is particularly intensified when amember of the coconut type oil family is added to liquid oils of othertypes. lntercstcrification reduces the tendency to SlltOh-l but not toan acceptable point, whereas the addition oi the silicone oil to the intercsterified product reduces the tendency towards smoking to thatnormally encountered in frying oils.

The product of the intercstcrification of. a mixture of coconut oil with20% cottonseed oil was washed. refined, bleached and deodorized. To thisproduct was added parts per million of methyl sil xane having aviscosity of 10,000 CCIIIlSlLOhCS. The smoke point of theintcresterificd product without silort'ane additive was 360 1 uponaddition of methyl siloxane as described above, the smoke point rose to385 F.

in CZLC some 'difiiculty arises in incorporating the siloxane compoundinto the oil being treated, a small amount of a compound such asglyccrine or propylene glycol may be used. These compounds act as mutualsolvents and appreciably aid in the dispersal of the siloxancs throuhcut the oil.

A .y known method of making the siloxanes may be us' l. such the processdescribed by Burkhard and ilocltow in an article entitled The "resentState of Organosilicon Chemistry in Chemical Reviews, vol. 41 -10. I.August 1947. A coconut type oil may be intercsterilicd with bothvegetable and animal oils such as corn, peanut, tallow or others. Alsothe relative amounts of such oils may be varied within wide limits.General- 1y speaking, the amount of mutual solvent used is quite small,being not over about 5 parts based on the oil.

W1" only certain specific embodiments of this invention have beenspecifically disclosed, nevertheless the subjcct matter thereof is to bebroadly construed and not to be limited except by the character of theclaims appended hereto.

This application is a continzmrion-iiz-part of application Serial No.342,888, filed March 17, 1953, new uiiondoncd.

What is claimed is:

l. A fully glyceridc for use in deep fat frying of foods havingdispersed therein a. compound taken from the class consisting of methyland ethyl siloxanes, the amount of said methyl siloxane being from l to25 parts per million and having a viscosity of 1,000 to 100,000centistolaes at 100 F, the amount of said ethyl siloxane being from 5 to45 parts per million and having a viscosity of 1,000 to 100,000ccntistokcs at 100 F, said siloxanes not imparting any odor duringfrying operations, said compositions effectively raising the smoke pointfrom to 35 F. during a relatively large number of fryings.

2. A fatty glyceride according to claim 1, taken from the classconsisting of cottonseed, corn, peanut, soya bean and coconut type.

3. A fatty glyceride according to claim I, wherein the methyl siloxaneis present in an amount of from 5 to parts per million and the ethylsiloxane is present in an amount of from 15 to 4-5 parts per million.

t. A fatty glyceride according to claim 1 wherein said oil contains amutual solvent for the constituents thereof taken from the classconsisting of glycerine and propylene glycol.

5. A fatty glyceride according to claim 1 composed of a coconut type oilintcrcstcrified with another fatty acid triglyceride oil.

6. A fatty glyccride according to claim 1 wherein the glyceridc is acoconut type oil.

7.1% fatty glyccride according to claim 1 wherein said glyceride is cornoil.

8. A deep fat frying oil according to claim 3 wherein the methylsiloxane has a viscosity of from 1,000 to 30,- 000 centistoltes at 100F. and the ethyl siloxane has a viscosity oi 10,000 to 50,000centistoltcs at 100 F.

9. A deep fat frying oil according to claim 4 wherein the mutual solventis present in an amount not over 5 parts bus-d on said oil.

10. A fatty c'I vr'c'rfdB adapted for use in the frying, of fluids[roving u'iwrrsm lln'rr'ilz a compound mile from tin (lusts (ou fall/ix:of methyl (1/!!! ethyl i/orzi/tes, the amount of said lilt'ill wl.ri/ctt'rme l ving; front 1 to ports 5 per million and having aviscosity of 100 to 100,000 centistoices at 100 F., the amount of saidethyl siloxane being from 5 to 45 parts per million and having aviscosity 0 100 to 100,000 centistokes at 100 F.

11. A method of frying foods which comprises providing a mixture of afatty glyceria'e having dispersed therein a compound taken from theclass consisting of methyl and ethyl siloxanes, the amount of laidmethyl siloxane being from 1 to 25 parts per million and having aviscosity of 100 to 100,000 centistoices at 100 F., the amount of saidethyl siioxane being from 5 to 45 parts per million and having aviscosity of 100 to 100,000

CfiftlilsZOh'CS at 100 F., heating said mixture to u sufjiciently hightemperature to fry foods, and then introducing into said mixture (1 foodto be fried.

References Cited in the file of this patent or the original patentUNITED STATES PATENTS Martin Apr. 7, 1953 OTHER REFERENCES TheWashington Post, Sunday, May 18, 1947, page 6B, paragraph beginningSilicone.

